The Republicans claimed they were from Northern Arizona University.
Photograph: Alamy

Two young Arizona Republicans tried to make a donation to a congressman while posing as members of a university communist party, in an apparent attempt to tie the Democrat to the far left.

On Friday afternoon in Flagstaff, two men who called themselves Jose Rosales and Ahmahd Sadia walked into the campaign office of first-term Democrat Tom O’Halleran, with $39.68 and an urgent desire for the “Northern Arizona University Communist party” to be given a receipt for the donation.

Sign up for the new US morning briefing

The pair walked in to sign up to volunteer but they brought along a jar full of money that they said they wished to donate. After being directed to a finance staffer, they were told to fill out paperwork. In doing so, they identified themselves as members of the Northern Arizona University Communist party. They made clear they were not an official group but were holding meetings. But they also insisted on a receipt.

When told they would only get an emailed receipt, Rosales scratched out one email address and wrote down another. The process raised eyebrows among O’Halleran’s staff.

Speaking to the Guardian, Coleman identified the second man as a field organizer for the Arizona Republican party and said Ahmahd Sadia was not his real name. The Guardian later learned that the man had been fired from his job with the party.

In a statement sent to the Guardian on Thursday morning, a spokesman for O’Halleran’s Republican opponent, Wendy Rogers, said: “This is news to us. No one from our campaign was involved in this juvenile stunt.

“We are focused on defeating Tom O’Halleran and the Democrats this November and don’t have time for juvenile pranks,” said Spence Rogers. “We are more concerned about exposing Tom O’Halleran’s open borders liberal record.”

Making federal campaign contributions under a false identity is a crime. As a dirty trick, attempts to smear opponents by linking them to unsavory political groups has a long history.

In 1972, Roger Stone, then a young campaign staffer for Richard Nixon’s re-election campaign, sent a donation to Nixon’s anti-war primary opponent in the name of the Young Socialist Alliance. Stone went on to become a political adviser to Donald Trump, a role he left early in Trump’s 2016 presidential campaign.

Trump won the rural Arizona district narrowly, as did Mitt Romney in 2012. The non-partisan Cook Political Report now classifies the race as Likely Democratic.